[citation needed] Sources: Williams played in the first four games of the 2006 football season, splitting time with senior quarterback Tim Brasic.

On September 30, 2006, Williams led the Illini on a game-winning 4th-quarter drive for a 39-yard field goal that gave the team a 23–20 upset victory over host Michigan State.

Williams had average numbers in Illinois' back-to-back victories against ranked teams, defeating Penn State and Wisconsin.

It seemed as if Illinois' promising 5–1 start may have been a fluke, as they proceeded to drop their next two games, a 10–6 loss at Iowa and a 27–17 defeat against Michigan in Champaign.

Williams amassed over 350 yards of offense en route to a 41–22 victory over in state rival Northwestern in the regular season finale.

Illinois entered the 2008 season ranked as the #20 team in the nation, despite the loss of Big Ten MVP Rashard Mendenhall.

The Illini would pick up their first win of the season vs Eastern Illinois, where Williams amassed 174 yards rushing with 2 touchdowns in the 47–21 victory.

After a bye week (the first at Illinois under Ron Zook), the Illini traveled to Penn State and fell 38–24, with Juice passing for 183 yards and rushing for another 64.

The Illini fell flat vs Minnesota the following week, losing 27–20 despite Williams throwing for a career-high of 462 yards along with 2 touchdowns.

On August 3, 2009, Williams was named to the 2009 Davey O'Brien National Quarterback Award Watch List.

Then On August 27, 2009, Williams was named to the 22-man watch list for the 2009 Johnny Unitas Golden Arm award, given to the nation's top senior signal-caller.

During that game Juice Williams surpassed former Illini Jack Trudeau to become second in team history with 56 career touchdown passes.

When the Slaughter decided to sit out the 2014 season, Williams signed with the Chicago Blitz of the Continental Indoor Football League.